Axial air gap alternators/generators of modular construction

ABSTRACT

Alternators/generators of axially disposed air gap conformity in which a unique combination of rotors and stators results in machines of high efficiency, simplified modular assembly and extension. Such machines can, moreover, be readily constructed to produce from a single alternator unit multiple voltages and frequencies and from a single generator unit direct current in multiple voltages.

This invention relates generally to alternators and generators and inparticular to the type wherein the cooperating magnetic components ofrotor and stator are set apart across an axially disposed air gap.

In keeping with my U.S. patent application Ser. No. 843,936 filed onOct. 20, 1976, this invention is dedicated to improvements inalternators/generators of the axial air gap type, with said improvementsincluding the following more specific areas of objective endeavor:

Providing the capability to increase the capacity of machines of thetype referred to by modular extension, with added modules possessingsimilar or dissimilar characteristics of voltage, frequency and currentto the existing module or modules.

Providing the capability of producing electrical energy of divergentvoltages, frequencies and current from single modules.

Providing single units having rotors of both permanent magnet andelectromagnet conformity.

Providing multi-pole rotors including high frequency types from a singletwo pole ring or sleeve type permanent magnet.

Providing multi-pole rotors including a high frequency type from asingle coil electromagnet.

Providing magnetic iron of simplified configuration including a castabletype.

Providing windings of simplified configuration.

Providing a means of cooling the output windings of analternator/generator by placing the windings in direct contact with acooling liquid or gas.

In the invention as outlined within this specification and theaccompanying drawings, two cardinal embodiments of the invention areevidenced and will hereinafter be referred to respectively as Embodiment"A" and Embodiment "B", with Embodiment "A" being shown in main in FIG.1 and Embodiment "B" being shown in main in FIG. 14. In Embodiment "A"the path for magnetic flux return is provided by the stator iron only,while in Embodiment "B" the magnetic flux is in general returned bymeans of rotor interaction. However, a variant of Embodiment "B" asillustratively shown in FIG. 27 provides means for flux return via thestator iron.

GENERAL DESCRIPTION OF THE DRAWINGS

FIG. 1 is a longitudinal sectional view showing certain principalfeatures of the invention as applied to Embodiment "A". The magneticfield herein is indicated as being furnished by an electromagnet.

FIG. 2 is a cross sectional view taken on Line 2 of FIG. 1 for thepurpose of showing the radial orientation and location of the statoriron and coils.

FIG. 3 is a fragmented view taken on Line 3 of FIG. 2 and shows furtherdetail of the stator iron with the output coils removed.

FIG. 4 is a sectional view on an intermediate stator plate and includesdetails of the stator iron and securing means for same. This detail isapplicable to Embodiment "A" only.

FIG. 5 is an end view on a shaft, solecore and field coil assembly foran electromagnetic rotor and is applicable to both Embodiments "A" and"B" of the invention.

FIG. 6 is a longitudinal sectional view taken on Line 6 of FIG. 5.

FIG. 7 is an end view on a shaft, non magnetic spacer and ring typepermanent magnet for a permanent magnet type rotor and is applicable toboth Embodiments "A" and "B" of the invention.

FIG. 8 is a longitudinal sectional view taken on Line 8 of FIG. 7.

FIG. 9 is a side view on a rotor pole unit for function in a singlestator machine of Embodiment "A" conformity.

FIG. 10 is an end view on FIG. 9 taken on Line 10.

FIG. 11 is an end view on FIG. 9 taken on Line 11.

FIG. 12 is a side view on a rotor pole unit for a multiple statormachine of Embodiment "A" conformity.

FIG. 13 is an end view on FIG. 12 taken on Line 13.

FIG. 14 is a longitudinal sectional view showing the salient componentsand their relationship to each other as applies to Embodiment "B" of theinvention.

FIG. 15 is a cross sectional view taken on Line 15 of FIG. 14 for thepurpose of showing the radial orientation of the stator iron and coilsand their location within the unit's casing. In the interest of claritythe unit's rotor has not been shown in this view. FIG. 15 applies onlyto Embodiment "B" of the invention.

FIG. 16 is a side view on a stator iron "bundle" for a multiple rotormachine of Embodiment "B" conformity.

FIG. 17 is an end view on FIG. 16 as viewed on Line 17.

FIG. 18 shows a stator iron "bundle" for a single rotor machine ofEmbodiment "B" conformity.

FIG. 19 is an end view on FIG. 18 as taken on Line 19.

FIG. 20 is a side view of a rotor pole unit assembly applicable toEmbodiment "B" of the invention.

FIG. 21 is an end view on FIG. 20 as taken on Line 21.

FIG. 22 is an end view on FIG. 20 as taken on Line 22.

FIG. 23 is a side view of a permanent magnet type rotor applicable toboth Embodiments "A" and "B" of the invention.

FIG. 24 is a face view on FIG. 23 taken on Line 24.

FIG. 25 is a front view on a flux return ring of laminated constructionand applicable to Embodiment "B" of the invention.

FIG. 26 is a longitudinal sectional view on FIG. 25 taken on Line 26.

FIG. 27 is a fragmented sectional view generally on Line 27 of FIG. 14and supplements FIG. 14 to the extent that it shows a flux return ringin location and moreover provides detail of the machine's support footwhich forms an integrated part of the end cap.

FIG. 28 shows an intermediate rotor support as would be generally viewedon Line 28 of FIG. 14. This figure is applicable to Embodiment "B" ofthe invention only.

FIG. 29 is a longitudinal fragmented section showing details of a casingend which has been modified to allow for modular extension of a machineconstructed in accordance with Embodiment "B" of the invention.

FIG. 30 is a fragmented view taken on Line 30 of FIG. 29 and mainlyserves to show detail of the machine's support foot incorporated in thecasing end as reflected in FIG. 29.

FIG. 31 is a fragmented cross sectional view on the casing of a machineof Embodiment "B" conformity, and shows the means of securing the outercasing to the inner casing.

FIG. 32 is a longitudinal sectional view taken on Line 32 of FIG. 31showing additional detail to that given in FIG. 31.

FIG. 33 is an isometric view of a rotor pole unit assembly of the typeshown in FIG. 12 and which has been provided in order to show greaterdetail of the means whereby dissimilar polarities are obtained at oneface of a basic electromagnet as shown in FIGS. 6 and 8.

FIG. 34 is a front view showing details of a rotor pole unit to be usedin a machine of Embodiment "B" conformity for the production of directcurrent electricity.

FIG. 35 is a cross sectional view on FIG. 34 as taken on Line 35.

FIG. 36 is a sectional view on a stator plate and shows means whereby acoolant can be placed in contact with the output coils or windings of amachine of Embodiment "A" conformity.

FIG. 37 is a fragmented view taken on Line 37 of FIG. 36.

DETAILED DESCRIPTION OF THE DRAWINGS AND EMBODIMENTS OF THE INVENTION

In FIG. 1 of the drawings the main components of an alternator/generatorof Embodiment "A" conformity are shown with said components beinglocated in functional relationship to each other.

A casing 12 of cylindrical conformity has its ends prepared to receiveand accomodate end plates 11, said end plates being of a non magneticmaterial and serving the multiple purposes of structurally supportingcasing 12, retaining bearing means 10 and structurally supporting andretaining a ring of laminated magnetic metal 15 hereafter referred to asthe "stator iron", said stator iron 15 being secured to the end plate 11via the medium of stator iron securing ring (outer) 17 and stator ironsecuring ring (inner) 18, said rings 17 and 18 being constructed of nonmagnetic material and fastened to end plate 11 by securing screws 19.The stator iron 15 is in turn retained between securing rings 17 and 18by bolt 20 and nut 21, both of said items being of non magneticmaterial. A study of FIGS. 1 and 2 will further show that statorinductor coils 16 are wound about the teeth of the stator iron 15, saidteeth being shown in greater detail in FIG. 3. Referring again to FIG. 1it will be noted that bearing 10 locates and retains a rotatable shaft 3of non magnetic material to which a rotor assembly 1 of theelectromagnetic type is secured by retaining screws 4, said screws beingof magnetic material.

In considering the construction of the rotor assembly 1, FIGS. 5 and 6detail a solecore 2, of magnetic material, having a coil of wire 60wound about its periphary and across its length for the purpose ofco-operating with the solecore 2 to create a magnetic field, thenorth-to-south and south-to-north orientation of which would parallelthe rotor shaft 3. Coil 60 is provided with terminals 5 and 6 which areled through a hollow section of shaft 3 to brush gear rings 24 and 25which are retained by an insulating cement (not enumerated) in a ringgear body 22 which in turn is secured to rotatable shaft 3 by securingscrew 23. Direct current electrical supply to coil 60 is led (from asource not shown) to brush gear rings 24 and 25 via terminal posts 28and brushes 26 and 27. All brush gear components are protected by brushgear cover 29 which is secured to end plate 11 by securing screws 61.Brush gear terminal posts 28 are insulated from brush gear cover 29 byinsulator 63.

In order to usefully direct the magnetic field eminating from the basictwo-pole, two-pole face magnet formed by the cooperation of field coil60 and solecore 2, a pair of special rotor pole units 7 and 8 (shown inFIG. 12) of magnetic material have been provided and secured to the polefaces of solecore 2 by securing screws 9. The rotor pole units 7 and 8are constructed as follows:

A disc which has its diametrical dimension placed at 90° to thelongitudinal axis of solecore 2, incorporates substantially at itsperiphery a plurality of fore and aft directed fingers of square orrectangular cross section, said fingers being radially disposed withregard to the longitudinal center line of solecore 2 and equally spacedabout said disc's periphery.

By reference to FIGS. 1 and 12 it will be noted that the above referredto fingers are of unequal extension fore and aft of the faces of thedisc with which they are integrated, and have their major length ofextension equal to the longitudinal dimension of the solecore 2 plus thedimension of the reciprocal extension as measured from the face of thedisc establishing contact with the pole face of solecore 2. By referringto FIGS. 12 and 13 it will, moreover, be noted that crescent shapedopenings are in evidence in that portion of the pole unit disc locatedadjacent to its periphery, and with the radial center lines of saidopenings being spaced at equal distance between each pair of fingersintegrated with the disc in which the openings are evidenced. Thepurpose of the afore discussed openings is to receive the fingers orpoles, of a pole unit of equated physical structure, located at theopposite end of the solecore 2 and secured thereto.

Since the fingers of the pole units located at opposite ends of thesolecore 2 will obviously be of opposite polarities, the crescent shapedopenings are dimensionally calculated to eliminate magnetic shortcircuiting and to minimize flux leakage between pole assemblies.

In function as a multi-pole rotor assembly 1 of the electromagnetictype, the magnetic field eminating from the north pole of solecore 2(the appropriate direction of winding field coil 60 being observed) istransferred to the disc portion of rotor pole unit 8 from which thefield then flows via the pole fingers of said rotor pole unit 8 in bothdirections of extension of said fingers, then flows to the south poleface of solecore 2 via the air gap at both stators, aligning teeth ofthe stator iron 15, and fingers of rotor pole unit 7. It will be notedthat while the fore and aft extension of any pole finger is unequal, thetotal distance of flux flow from a north to a south pole transverses anequal distance and an equal volume of magnetic material. The reluctanceof the magnetic circuit is therefore in balance.

FIGS. 9, 10, and 11 reflect a modified version of the rotor pole unit asafore discussed and as shown in FIGS. 1, 12, 13 and 33. The modifiedversion, comprising part of rotor assembly 30, is designed for operationin machines of single stator conformity and varies from the earlierdiscussed pole units 7 and 8 mainly in that the pole fingers extend inone common direction only from the disc portions with which they areintegrated. The individual rotor pole units enumerated 31 and 32respectively, moreover have pole fingers of unequal length, 31 havingthe longer fingers in view of their having to traverse the length of thesolecore 2, in order to maintain the pole faces of both magnetpolarities in a common plane. It should be noted that the modified poleunits 31 and 32 have been conceptually structured to utilize the samesolecore 2, and field coil 60, as rotor pole units 7 and 8 in order toform a complete electromagnet assembly 30 as required in the function ofan alternator/generator variant of Embodiment "A" of the invention. Bothrotor pole units 31 and 32 are secured to solecore 2 by securing screws9.

A modification to both types of rotors as previously described is asfollows:

A spacer sleeve of non magnetic material 33, as shown in FIGS. 7 and 8is substituted for solecore 2 and is affixed to rotatable shaft 3 bysecuring screws 34, said securing screws also being of a non magneticmaterial. A permanent magnet of ring or sleeve conformity 35, suitablydimensioned and magnetized in the direction indicated thus "←M→" andbeing of material such as cast Alnico VIII (but not necessarilyrestricted to same) is substituted for field coil 60 and is secured tospacer sleeve 33 by tapered keys 36. In this modification to the rotorsas previously discussed, rotor pole units 7, 8, 31 and 32 remainunchanged and said units would be secured to spacer sleeve 33 bysecuring screws 9. By the substitution of spacer sleeve 33 and permanentmagnet 35 for solecore 2 and field coil 60, field coil terminals 5 and6, brush gear rings 24 and 25, ring gear body 22, securing screw 23,brushes 26 and 27, brush gear terminal posts 28, brush gear cover 29,securing screws 61 and insulator 63 are eliminated from function in analternator/generator of Embodiment "A" conformity.

Yet another type of rotor highly suitable for providing the necessarymagnetic field for an alternator/generator of Embodiment "A" conformityis shown in FIGS. 23 and 24. In this latter instance, a disc of nonmagnetic material 52 has a plurality of permanent magnets 55, of squareor rectangular cross sectional geometry, approximating in said geometryand area, the cross sectional geometry and area of the stator ironteeth. Said permanent magnets 55 being longitudinally dimensioned inaccordance with design conditions and the individual permanent magnets55 located in suitably sized openings arranged on a pitch circlesubstantially coincident with the pitch circle of the stator iron 15.The permanent magnets 55 are retained in their accomodating openings bysecuring screws 56, said securing screws being of non magnetic material.By referring to FIG. 24 it will be seen that the permanent magnets 55are of an equal angular disposement about the faces of disc 52 and areof alternating magnetic polarities.

In utilizing a rotor of the type last described within the confines ofan alternator/generator of Embodiment "A" conformity, the previouslydescribed rotors, shafting and brush gear components would be excludedfrom the assembly and replaced with a permanent magnet type rotor 52,said rotor incorporating in its structure a hub and keyway as shown inFIGS. 23 and 24. In an operable installation, rotor 52 would be affixedto a suitably dimensioned rotatable shaft 47 by means of key 53 andsecuring screw 54. Shaft 47 would be located and retained by bearingmeans 10. Such an installation in combination with suitably dimensionedcasing 12 and tie rods 13 would place the rotor 52 in a centralizedposition between stator iron 15 located at both ends of the alternator,in which position the rotor when revolved by a suitable driver wouldcooperate with other system components for the production of usableelectrical energy.

In considering the four rotor types dealt with in the foregoing, it willbe apparent to those skilled in the alternator/generator art thatadequately constructed rotors of the conceptual principles aforediscussed, having their poles placed in rotational coincidence withstator iron as aforedescribed and detailed in the drawings, willadequately cooperate with said stator iron to produce a magnetic fluxwithin the teeth or poles of the stator iron which in turn will reactwith the induction coils 16 to produce electrical energy in the form ofalternating current.

In order to reduce manufacturing costs and expedite unit assembly on amachine of Embodiment "A" conformity, the following means of increasingoutput capacity by simple addition of standardized components has beendeveloped and is a feature of this invention.

In FIG. 4 a stator plate 37 of general configuratory similarity tostator plate 11 is indicated. It will be noted however, that plate 37has both of its faces prepared to receive a casing section 12 and hasstator iron 15 secured to both of its faces by securing rings 17 and 18,and a bearing 64 is moreover positioned and retained in accordance withdetails indicated for end plate 11. In order to increase the outputcapacity of a machine by modular extension, one end plate 11 would beomitted from a unit assembly and replaced with an intermediate statorplate 37. If the unit to be extended employs a rotor of theelectromagnet type, the omitted end plate 11 would be the one at theopposite end to the machine's brush gear assembly. In all instances ofmodular extension the unit's shaft 3, or 47, dependent upon the type ofrotor to be used, would be suitably extended in its longitudinaldimension and in the case of a shaft for a machine utilizing a rotor ofthe electromagnetic type, the hollow section which accomodates therotors' terminal leads 5 and 6 would also be suitably extended. With theinstallation of a suitably extended shaft 3 or 47, and having locatedand secured same at one end of the machine, in an end plate 11, said endplate being located in suitable relationship to a casing segment 12, arotor of the required type would then be located and secured to theunit's shaft, and intermediate stator plate 37 would now be installed,followed by a further rotor of suitable conformity, and in the case of amachine of two rotor/four stator configuration, a suitably dimensionedcasing segment 12 and a further end plate 11. Casing segment 12, statorend plates 11 and intermediate stator plate 37, would now be secured byproperly dimensioned tie rods 13 together with securing nuts 14. In anassembly as last described, it should be noted that rotor stability isvirtually assured by the intermediate bearing 64, and assuming equal airgaps between the faces of the rotor and stator iron, no end loads wouldbe imposed upon the bearings 10 and/or 64.

In the example of modular extension cited in the foregoing, a situationconsidering a two rotor/four stator unit has been dealt with, but itwould be obvious that unit extensions exceeding the quantity of rotorsand stators cited in the example is possible, but in such instance,longitudinal reinforcement of a unit's casing (not shown) would berequired to establish structural stability of a machine of yet furtherextended modular configuration. It would also be apparent that byomitting stator iron 15, induction coils 16, stator iron securing rings17 and 18 together with securing screws 19, bolt 20 and nut 21 from oneend plate 11 and utilizing a rotor assembly 30, of a permanent magnettype rotor 52, in conjunction with a suitably dimensioned casing 12 andlikewise suitably dimensioned tie rods 13, a foreshortened single statormachine would be constructable. Moreover in constructing a machine ofmodular extension, it would also be apparent that rotors of divergenttypes and/or of different pole numbers could readily be incorporated ina single assembly making practical a wide variety and range of outputconditions.

A further feature of the invention as applicable to Embodiment "A" ofsame is a means whereby cooling of the machine's output coils can beachieved.

In FIG. 36 a typical stator plate 37 is indicated, said plate carryingstator iron 15, stator iron securing rings 17 and 18 together withoutput coils 16. It will be noted however that said items 15, 16, 17 and18 have now been enclosed within a coolant containment area bounded inmain by stator plate 37, gasket 77 and coolant containment channel 74,said coolant containment channel 74 (constructed of non magneticmaterial) and gasket 77 being secured to stator plate 37 by securingscrews 78. By further reference to FIGS. 36 and 37, the latter figureserving to further detail the means whereby cooling of the output coilscan be achieved, it will be discerned that the containment channel 74comprises a channel of "doughnut" conformity having a plurality ofopenings cut in the web member of said channel in order to receive thefingers of the stator iron 15, while the channel sides at its open endbear outwardly directed integrated flanges encompassing the totaldeveloped length of the channel, said flanges being in purpose designedto facilitate the securing of the said containment channel 74 to thestator plate 37. The containment channel 74 is moreover provided with acoolant inlet connection 75 and a coolant outlet connection 76, bothconnections being integrated with said containment channel 74 andprovided with means for receiving the threaded ends of pipes functioningto supply and discharge the coolant received in the containment area.

In a machine provided with cooling means as described herein, the statoriron 15 and output coils 16 would be enclosed in an envelope of epoxyprior to their being integrated with the stator plate 37 following whichthe containment channel 74 would be located in position with gaskets 77being located between the flanges of said containment channel 74 and thestator plate 37. The containment channel 74 would now be secured to thestator plate 37 by securing screws 78, and a fillet of epoxy would beapplied to all areas of intersection between the stator iron teeth andthe web of the containment channel 74 thereby forming a sealedcontainment area except for the inlet and outlet connections enumerated75 and 76 respectively.

Having secured the containment channel 74 in the manner as lastdescribed, a coolant inlet pipe 97 supplying coolant (from a source notshown) and a coolant outlet pipe 80 discharging the warmer coolant, bothhaving ingress to the containment channel 74 through suitablydimensioned openings in casing 12 are threaded into coolant inlet andoutlet connections 75 and 76, thereby completing the construction ofmeans whereby cooling of the output winding of a machine of Embodiment"A" conformity can be achieved.

In consideration of the coolants utilizable for the system as aforedescribed, it would be apparent that fluids in either liquid or gaseousstates could be effectively used provided adequate attention was givento details of temperature, velocity and flow volume.

It should be noted that while the example of system cooling means dealtwith in the foregoing refers to and details cooling of the output coilson one side of a stator plate 37 only, it would be readilyunderstandable that such cooling means could be applied to both sides ofan intermediate stator plate 37 and/or to a stator end plate 11, therebymaking possible the cooling of the output coils inalternators/generators of modular extension.

In FIG. 14 a longitudinal cross sectional view of the second majorembodiment of the invention hereafter referred to as Embodiment "B" isshown. In this view certain major components of this latter embodimentof the invention are shown in their relationship to each other.

In the afore referred to FIG. 14 a casing assembly 42, of non magneticmaterial is indicated, said casing comprising an inner section 66 ofelongated cylindrical form, contained within the confines of a radiallyset apart outer section 67, also of elongated cylindrical form, buthaving a pair of flanges encircling its periphery, said flanges beinglocated in near proximity to its ends and having a plurality of tappedholes disposed about their faces for the purpose of receiving bolts usedto secure the machine's end closure means 41 to the casing assembly 42.Also included in the casing assembly 42, is a plurality of "Z" shapedrib members of non magnetic material 68, such rib members having alongitudinal dimension substantially equal to the longitudinal dimensionof the casing inner and outer sections 66 and 67. The said rib members68 are shown in FIGS. 31 and 32 and function to maintain apart casingsections 66 and 67, and are in radial dispersement equidistant withinthe area separating the inner and outer casing sections 66 and 67. Byfurther reference to FIGS. 31 and 32 it will be noted that rib member 68is secured to inner casing section 66 by spot welding and secured tocasing outer section 67 by a plurality of securing bolts 69, said boltsbeing the fourth and final item comprising the casing assembly 42.

In FIGS. 16 and 17 a "bundle" of laminated magnetic iron 44 isindicated, said magnetic iron being equal in its longitudinal dimensionto that of casing assembly 42, and in cross sectional geometry beingsubstantially of rectangular conformity. FIG. 16 also indicates that themagnetic iron "bundle" 44 is maintained in unitary assembly by retainingrivets 45, said rivets being of non magnetic material. By referringagain to FIGS. 14 and 15 it will be noted that a plurality of laminatedmagnetic iron "bundles" 44, having first had an induction coil 46 woundabout their outside surfaces, have been located in the open area lyingbetween the inner and outer casing sections 66 and 67 of casing assembly42, and retained therein by retaining screws 65, said screws being ofnon magnetic material.

The combined magnetic iron "bundles" 44 and induction coils 46 are inequal radial dispersement between the inner and outer casing sections 66and 67 of the casing assembly 42; and, in longitudinal location, thefore and aft faces of the iron "bundles" 44 are in coincidence with theends of the casing assembly 42.

By referring again to FIG. 14 it will be seen that twin rotor assemblies38, said rotor assemblies being of the electromagnetic type, areprovided in order to furnish the necessary magnetic flux for interactionwith the magnetic iron 44, and induction coils 46, in order to effectthe generation of electrical energy. In considering the construction ofa rotor assembly 38, of the electromagnetic type as shown in FIG. 14, asolecore 2 and a field coil 60 as shown in FIGS. 5 and 6, and aspreviously described in relationship to Embodiment "A" of the invention,are suitably affixed to a rotatable shaft 62, said shaft being ofsuitable dimension and provided with a hollow section in order toaccomodate the terminal leads 5 and 6 of the field coil 60, said leadsbeing for the purpose of supplying direct current electrical energy froma brush gear apparatus in all respects similar to that described inrelation to Embodiment "A" of the invention.

In order to direct the magnetic field emanating from the simple twopole/two face magnet formed by the cooperation of field coil 60 andsolecore 2, to a single face magnet of multiple alternating north andsouth poles, a pair of dissimilar rotor pole units 39 and 40 areprovided in accordance with details illustratively shown in FIGS. 20, 21and 22.

In FIG. 21 a side view of a composite pole unit, consisting of northpole unit 39, and south pole unit 40 is in evidence. In FIG. 21 a frontview (from the north pole unit's face) shows the configuration of thenorth pole unit as being in the form of a modified cross, therelationship of its secondary dimension, appearing in the form of a flatplate and bearing the designation "N" is evidenced in FIG. 20. In anassembled rotor, the north pole unit 39, would be centered about shaft3, and secured to solecore 2 by securing screws 9. By referring again toFIGS. 20, 21 and 22 it will be seen that the rotor's south pole unit 40,is of a more complex structure, consisting of a disc sectionincorporating in substantial proximity to its periphery, a plurality offingers or poles, said fingers or poles being in equal radialdispersement about the periphery of said disc and extending in thedirection of the rotor's north pole unit, to the first point ofintersection with same, whereat, said fingers are made to effect a 90°outward radial change of direction, bringing them into parallelalignment with the rotor's north pole as viewed in FIG. 20. Upon beingcentered with respect to solecore 2, the rotor pole unit 40 is securedto said solecore 2 with securing screws 9. By referring again to FIG. 21it will be seen that both the north and south poles of the rotor asassembled, are in radial symmetry and configuration of the north poleunit 39 is such as to circumvent magnetic short circuiting to thefingers or poles of south pole unit 40.

In order to impart structural stability to the rotating elements of amachine of the conformity reflected in FIG. 14, an intermediate rotorsupport means has been provided, said rotor support means, shown in bothFIGS. 14 and 28 comprises bearing support plate 58 and bearing 10,bearing support plate 58 being of disc conformity with bearing 10 beingretained about its center. In function, the support element is locatedon the inside of casing assembly 42, substantially equidistant from theends of said casing assembly, and is secured to said casing assembly 42,by a plurality of bolts 59, the threaded ends of which engage in aninwardly projecting flange forming an integral part of inner casing 66.Being so located and secured, and having bearing 10 encompassing shaft62, it will be apparant that substantial structural stability has beenimparted to the machine's rotating elements by the afore describedcomponents.

Also shown in FIG. 14 is a pair of end plate or end cap means 41, saidmeans serving in main to integrate the rotating and static elements of amachine of Embodiment "B" conformity. It will be noted that a flangesection is embodied in said means 41 for the purpose of facilitating thesecuring of said means 41 to casing assembly 42, and a bearing means 10,is retained about its center. By reference to FIG. 15 it will moreoverbe noted that a support foot for the purpose of supporting the machine'sstructure, or securing same to a base such as the floor of a building,has been integrated in end cap means 41. It should also be noted thatwhen required, openings may be incorporated in the end cap means 41 forthe purpose of bringing the terminals of the machine's output coils 46to the outside of the machine.

Referring again to FIG. 14 and having described casing assembly 42, therotor assemblies 38, intermediate rotor support means 58 and 10, shaft62, stator iron 44, inductor coils 46, end caps 41 and means ofsupplying direct current power to the rotor's field coils 60, and havingdescribed the methods whereby the immediately afore listed componentsare located and secured in their relationship to each other, it will beseen that by moreover securing end plate means 41, together with endbearings 10 to casing assembly 42 by bolts 43, a funtionalalternator/generator of Embodiment "B" conformity will have beenconstructed.

It is important to note that in assembling a machine of Embodiment "B"conformity as shown in FIG. 14, and in order to provide a return pathfor the magnetic flux eminating from the north pole of rotor assemblies38, said rotor assemblies should be affixed to the shaft 62 in suchmanner that fingers or poles of opposite polarity are at all times inlineal alignment; or as otherwise expressed, opposing poles should atall times be coincident with the opposing ends of any magnetic iron"bundle" 44.

As in the instance of machines of Embodiment "A" conformities, rotors ofdivergent characteristics are adaptable to the basicalternator/generator of Embodiment "B" conformity as shown in main inFIG. 14, and substitutions as described in the following may be effectedin order to achieve a certain condition of design requirement.

A spacer sleeve of non magnetic material as shown in FIGS. 7 and 8 issubstituted for solecore 2, and is affixed to rotatable shaft 62 bysecuring screws 34, said securing screws also being of a non magneticmaterial. A permanent magnet of ring or sleeve conformity 35, suitablydimensioned and magnetized in the direction indicated thus "←M→" andbeing of a material such as Alnico VIII (but not necessarily restrictedto same) is substituted for field coil 60 and is secured to spacersleeve by tapered keys 36. In this modification to rotor assemblies 38as shown in FIG. 14, rotor pole units 39 and 40 would remain unchanged,and said units would be secured to spacer sleeve 33 by securing screws9. By the substitution of spacer sleeve 33 and permanent magnet 35 forsolecore 2, all means for supplying direct current power to field coil60 would be eliminated from function.

Another type of rotor highly suitable for providing the necessarymagnetic field for an alternator/generator of Embodiment "B" conformityis shown in FIGS. 23 and 24. In this latter instance, a disc of nonmagnetic material 52 has a plurality of permanent magnets 55, of squareor rectangular cross sectional geometry, approximating in said geometryand area the cross sectional geometry and area of the stator iron"bundles". Said permanent magnets 55 being longitudinally dimensioned inaccordance with design conditions, and the individual permanent magnets55 located in suitably sized openings arranged on a pitch circlesubstantially coincident with the pitch circle of the stator iron 44.The permanent magnets 55 are retained in their accommodating openings bysecuring screws 56, said securing screws being of non magnetic material.By referring to FIG. 24 it will be seen that the permanent magnets 55,are of an equal angular disposement about the face of disc 52 and are ofalternating magnetic polarities.

In utilizing rotors of the type now described within the confines of analternator/generator of Embodiment "B" conformity, the previouslydescribed rotors, shafting and brush gear components would be excludedfrom the assembly and replaced with permanent magnet type rotors 52,said rotors incorporating in their structure a hub and key as shown inFIGS. 23 and 24. In an operable installation, rotors 52, being locatedsubstantially in the area occupied by rotor pole units 39 in FIG. 14,would be affixed to a suitably dimensioned rotatable shaft 62 by meansof key 53 and securing screw 54. Shaft 62 would be located and retainedby bearing means 10 with said bearing means being retained in end plate41. Upon securing end plates 41 to the casing assembly 42 by means ofsecuring bolts 43, yet another variant of Embodiment "B" of theinvention will have been constructed.

In FIGS. 34 and 35 details of yet another rotor pole unit 73 isevidenced, the said pole unit, constructed of a magnetic material, hasbeen conceptually structured to cooperate with an electromagnet asformed by solecore 2 and field coil 60, shown in FIG. 6, and/or apermanent magnet 35, as shown in FIG. 8 in order to produce directcurrent electricity from a machine of Embodiment "B" conformity withoutresorting to output collector brushes. By examination of FIGS. 34 and35, it will be noted that pole unit 73 is of modified disc conformity,having a plurality of equally spaced and geometrically and dimensionallyequated "cut outs" extending inward from the periphery of the disc, andserving to define a plurality of outwardly directed fingers, the radialcenter lines of said fingers being of equal angular dispersement. Infunction as an electromagnetic type rotor, a pair of pole units 73,located within the confines of a machine of Embodiment "B" conformity,and placed substantially in the areas occupied by rotor pole units 39 asshown in FIG. 14, would be secured to solecore 2 by securing screws 9.

In this instance, solecore 2 (which would be secured to shaft 62 bysecuring screws 4) and field coil 60 would be of such longitudinaldimensional as to span the length of the stator iron "bundles" 44, plusthe sum of the air gap dimension at both ends of the stator iron. Infurther consideration of the rotor pole units 73, it should be notedthat the arc length of the fingers of said pole unit 73, as measured ona pitch circle coincident with the pitch circle at the center line ofthe stator iron, as viewed in FIG. 15, would be such as to ensure thatat any given time, a minimum of 50% of the stator iron "bundles", asviewed in cross section from the air gap, would be covered by the saidpole unit fingers. In an operating generator utilizing a rotor as lastdescribed, said rotor being supplied with direct current power to itsfield coil 60, in a manner as previously described herein, the rotorpole units 73, by the nature of their configuration, would createperiodic variations in the intensity of the magnetic field as they arerevolved, and thereby create an interaction with the stator iron 44 andthe induction coils 46 of such nature as to result in the production ofdirect current electrical power.

In a modified version of the rotor as last described, and again with thepurpose of generating direct current electrical power without resortingto collector brushes, a suitably dimensioned rotor sub-assembly ofpermanent magnet type, and comprising non magnetic sleeve 33, securingscrews 34, sleeve or ring type permanent magnets 35, all as shown inFIG. 8 is substituted for solecore 2, securing screws 4, field coil 60and all means of supplying said field coil 60 with direct current power.In an operating generator of Embodiment "B" conformity, a pair of rotorpole units 73 being secured to non-magnetic sleeve 33 by securing screws9 would perform an identical function to that described for theelectromagnetic type rotor as last dealt with herein.

In reviewing the means whereby magnetic flow is introduced to the statoriron of all variants of Embodiment "B" of the invention, as previouslydiscussed, it will be noted that in all instances, rotors or rotor poleunits have been located in rotatable circumstance at both ends of thestator iron "bundles" 44, with the purpose of such arrangement being toensure a path of magnetic flux return and/or to maximize machine output.In the event, however, of a requirement for machines of more limitedoutputs and/or due to circumstances of manufacture or economics, analternative method of obtaining flux return has been provided.

In FIG. 18 an alternative form of stator iron to that shown in FIG. 16is in evidence. The iron "bundle" 48 shown in FIG. 18 is formed fromlaminates, retained in unitary assembly by non magnetic rivets 45 and isin all respects similar to iron "bundle" 44 except that one of its endshas been bent through 90° in order to form a figure of "L" shapedconformity. It will moveover be noted by again referring to FIG. 18 thata punched hole is in evidence in the shorter leg of the "L" shaped iron"bundle" 48, said hole being located in near proximity to the end of thesaid iron "bundle". In FIG. 27, the method of installing the modifiediron "bundles" 48 in a single rotor machine is indicated. It will benoted that the shorter leg of the "L" shaped iron "bundles" 48 is turnedinward towards the machine's axis and in all instances would be locatedat the end of the machine opposite to the rotor and/or brush gear. InFIG. 25 and 26 a flat ring of laminated magnetic iron 49 is indicated,said ring having a plurality of holes disposed about its face on a pitchcircle coincident with the pitch circle established by the holescontained in the shorter leg of stator iron "bundles" 48 when installedin casing assembly 42 as previously described and as shown in FIG. 27.By cross reference of FIGS. 15 and 25 it will be noted that the numberof holes contained in the laminated iron ring 49 is equal to the numberof laminated stator iron "bundles" for a typical machine, therebyfacilitating the affixment of the individual stator iron "bundles" 48 tothe laminated iron ring 49 by locating bolts 50 and securing nuts 51 inthe manner as shown in FIG. 27. Having secured the stator iron "bundles"48 to the laminated iron ring 49 by means of bolts 50 and nuts 51, saidbolts and nuts being of a non magnetic material, an adequate return pathfor the magnetic flux emanating from the machine's rotor will have beenestablished without the incurrence of abnormal losses to residualmagnetism.

As in the instance of Embodiment "A" of the invention, and in order tomake available machines capable of providing a wide range of outputconditions of voltage, current and frequency from a single machinewhilst utilizing standardized components in its assembly, a method ofmodular extension as hereinafter described has been evolved for machinesof Embodiment "B" conformity, and is an object of the invention.

In FIG. 29 a modification to casing assembly 42 as shown in FIG. 14 isindicated. The modification referred to is applicable to one end ofcasing assembly 42 only, in effect a casing assembly 57 as detailed inpart in FIG. 29 would have the balance of its assembly in all respectssimilar to casing assembly 42 with said balance including in proximityto its longitudinal mid-section a means for receiving and securing anintermediate rotor support means, comprising bearing support plate 58and bearing 10. In the modification as detailed in FIG. 29, the innercasing section, now enumerated 70, incorporates in close proximity tothe end shown in FIG. 29, an inwardly projecting flange to which anintermediate rotor support plate 58 is secured by securing bolts 59, thesaid rotor support plate 58 having a bearing means 10 retained about itscenter. By again referring to FIG. 29, it will be noted that the outercasing section of casing assembly 57, said outer casing section nowbeing enumerated 71, incorporates the following configuratorydifferences to a casing outer section 67 as shown in FIG. 14;

The flange portion of said outer casing section 71 has been extendedlongitudinally beyond the face of the stator iron 44 and a machinesupport foot (shown in greater detail in FIG. 30) has been incorporatedas an extension of said flange section.

In order to increase the output capacity of a machine of Embodiment "B"conformity of modular extension, a selected rotor would be located andsecured at an intermediate setting on an appropriately dimensioned shaft47 or 62, and a casing assembly 57, complete with a pair of rotorsupport means comprising bearing support plate 58 and bearing 10, onesaid rotor support being located at the mid-section of casing assembly57, and the other said rotor support means located as shown in FIG. 29,would be so positioned about the rotor and shaft assembly as to locatethe rotor with one of its faces being separated from the stator iron 44,as shown in FIG. 29, by a minimal working air gap only. In the next stepof assembling a machine of modular extension, a casing assembly 42,complete with a rotor support means comprising bearing support plate 58and bearing 10, secured in the proximity of its mid-section, would bepositioned about the as yet unenclosed portion of shaft 47 or 62, andcasing assemblies 42 and 57 would now be secured in unitary assembly bysecuring screws 43. By performing this last described operation ofassembly, the selected rotor as affixed to the machine's shaft would nowhave its pole faces separated from the faces of the stator iron"bundles" 44 as retained in casing assemblies 42 and 57 by a minimizedair gap of equal dimension. In the final steps of assembling the majorcomponents of a machine of modular extension of Embodiment "B"conformity, a pair of rotors of similar characteristics to the onediscussed in the immediate foregoing would now be secured to shaft 47 or62, one being located at either end of the machine, and having theirpole faces separated from the stator iron "bundles" 44 by a minimizedair gap. A pair of end cap means 41, having bearing means 10 retainedabout their centers, would now be secured to the end flanges of casingassemblies 42 and 57 respectively, by securing screws 43, and a machineof modular extension will now have been constructed.

In the example of modular extension cited in the foregoing, it will benoted that a two stator/three rotor assembly has been discussed, withthe rotors being of similar characteristics and the intermediate rotorobviously being of the two pole face type.

In an assembly as afore discussed, it would be apparent that the statoror casing assemblies 42 and 57 could obviously incorporate vastlydivergent types of windings or coils, which in turn could be connectedin various combinations to make available a wide variety of voltage andcurrent characteristics.

Upon reflection on the method whereby modular extension of a machine ofEmbodiment "B" conformity can be effected, it would also be apparentthat an assembly need not be limited to the two modules as used in theexample cited, and that moreover a variety of rotors, including bothpermanent magnet and electromagnet types can be utilized in a singlemachine of modular construction or extension.

For instance, intermediate rotors (rotors located between casingassemblies or modules) of the two pole face type, having equatedcharacteristics of field strength and pole numbers as discussed in theforegoing, could be replaced with twin rotor units, operating "back toback", with each rotor having divergent characteristics of fieldstrengths, pole numbers and/or field source; i.e., electromagnet orpermanent magnet, it would now be apparent that with such arrangements,a wide range of frequencies as well as voltages could be made availablefrom a single machine of modular construction. Additionally, currentcharacteristics from such machine could be widely divergent in nature,and could include direct current, in which case all or a portion of suchdirect current could be utilized to supply power to the field coils ofany electromagnetic type rotors being incorporated in the assembly, andin an instance where the magnetic field utilized to produce such directcurrent eminated from a rotor or rotors of permanent magnet type, analternator/generator characterized in part by rotors of theelectromagnetic type but which place no dependency on a source of directcurrent for field excitation outside of the said alternator/generatorwould have been constructed.

A further feature of the invention as applicable to Embodiment "B" ofsame concerns a means whereby a liquid or gaseous coolant can be readilyand safely applied to the output windings of a machine of Embodiment "B"comformity.

Because of the unique structure of the stator of a machine of Embodiment"B" conformity, wherein the stator iron and output coils are containedwithin the cavity formed between two cylinders, located one within theother, with said cylinders being equally spaced apart, a means whereby acoolant can be contained in flowing proximity to said stator iron andoutput windings can be effected in the following manner:

A pair of annular rings (not shown) of non-magnetic material andapproximately 1/8" thick have an outside diameter substantially equal tothe inside diameter of the outer cylinder and an inside diametersubstantially equal to the outside diameter of the inner cylinder, andhave a plurality of openings punched or otherwise cut on a pitch circlesubstantially coincident with the mean diameter of said annular rings,said openings being coincident in quantity, geometry and cross sectionaldimension with the quantity, geometry and cross sectional dimension ofthe stator iron "bundles" 44 are utilized as the basic structural meansfor forming an end closure between the inner and outer stator casingsections at both ends of the stator or casing assemblies 42 and/or 57.

In the first step of preparing a stator for operation, featuring directcooling of its windings, the sub-assemblies comprising the stator iron"bundles" 44 and induction coils 46 would be enclosed in a thin envelopeof epoxy prior to assembly and securing within the stator casingassemblies 42 or 57. Having located and secured the stator iron andinduction coils as last described, the previously discussed annularrings would then be located (at both ends of a stator section) withinthe openings between the inner and outer casings, and with the ends ofthe stator iron "bundles" 44 projecting approximately 1/4" beyond theoutside face of the said annular rings which would then be tack weldedto the inside and outside casing sections. Having secured the closurerings to the inner and outer casing sections as last described, allopenings in the basic end closure as now effected would be sealed withan epoxy, as would all areas of potential fluid leakage at stator ironsecuring screws 65. In an instance where stator iron "bundles" 48 are tobe installed in a machine requiring direct cooling of its outputwindings, the annular ring to be used for forming the basic end closurestructure at a stator end of the type shown in FIG. 27, would be made intwo sections, having a circumferential seam located on its meandiameter. After having installed the two sectional annular ring as lastdescribed, both sections would be structurally secured by tack welding,and all areas of potential coolant leakage sealed with an epoxy.

Having obtained a fluid tight stator cavity in the manner asillustratively afore described, and noting by reference to FIG. 32 thatopenings incorporated in casing rib members 68 would allow circulationof a coolant about the stator iron/induction coil assemblies, it wouldnow require only a fluid inlet connection to be provided, preferably onthe lower side and near one end of the stator outer casing 67 or 71 anda fluid outlet connection to be provided at an opposing side and end ofsaid outer casings 67 or 71, and a liquid or gas cooled stator ofEmbodiment "B" conformity would now have been constructed.

As in the instance of the cooling system incorporated in Embodiment "A"of the invention, the cooling system of Embodiment "B" can readilyutilize coolants in either gaseous or liquid states provided dueattention is rendered to such factors as temperature, velocity and flowvolume.

Yet another object of the invention involves a method whereby thelaminated iron forms 15, 44, 48 and 49 employed in the magnetic circuitof the stators of machines of Embodiment "A" and "B" of the inventionare replaced by forms of unitary construction with said unitary formsbeing manufactured by the processes of casting, extruding and/orpressing and sintering.

In a particular type of casting or extruding process, a liquid polymerwould be mixed with a ferritic powder, such powder having chemicalproperties suitable for the manufacture of magnetic iron, the mixingprocess would be such as to obtain a required dispersement of theferritic powder in a minimum quantity of liquid polymer, therebyminimizing the reluctance of the magnetic form. Upon completion of themixing process, the "green" mixture would be molded or extruded to thedesired finished shape or form.

In a further type of casting, ferritic powders being at a temperaturebelow their melting point are combined with certain molten non-magneticmaterials at selected predetermined temperatures whereupon the resultantfluidic mass is molded to the required form.

In producing magnetic iron forms by the process of pressing andsintering, a selective mixture of suitably granulated ferritic powder,non-magnetic metals powder and selected ceramic oxides of appropriategranular dimension and chemical properties, said oxides and non-magneticmetals having in final purpose the granular separation of the ferriticpowder in order to minimize losses due to residual magnetism in amagnetic circuit, would be formed to a finished shape under highpressure and then fused to an agglomerate by sintering.

To those skilled in the alternator/generator art, and in particularthose being aware of the problems associated with complex laminated ironforms, the advantages offered by the afore described alternative methodsof constructing magnetic forms would be manifest.

In considering the various concepts as set forth in this specificationand the accompanying drawings, it will be apparent that in the interestsof clarity and brevity only the more salient features of the inventionhave been illustratively described herein, and many modifications to thedetails shown and described may be readily effected. For instance, rotorpole numbers and shapes could be of a wide variety and output coilscould be connected in a variety of combinations in order to achieve awide range of output voltages and current conditions. The structuralelements of the machine as illustratively shown could also be subject tomany modifications.

I therefore state that having made the disclosure as set forth herein,including certain mechanical arrangements as shown in the drawings,which are merely indicative of certain approaches contemplated by myinvention, and being aware of the many modifications likely to appear tothose skilled in the art, that my invention is not limited to theembodiments illustrated and described herein, but further includes allmodifications and variations as may fall within the scope of thefollowing claims.

What is claimed is,
 1. An electrical generator comprising:(a) a generally cylindrical casing including two radially spaced-apart walls, (b) a plurality of individual elongated magnetic cores located between the casing walls, each core having an electrical coil wound around it, the cores and coils defining the stator of the generator, (c) a rotor within the inner of the casing walls, the rotor being rotatable about an axis parallel to the axis of the casing, the rotor having a plurality of radially projecting magnetic pole pieces, the magnetic pole pieces extending into axial alignment with the magnetic cores and being axially spaced from the ends of those cores, (d) whereby as the rotor rotates the magnetic cooperation between the pole pieces and cores generates electric current in the stator coils on the cores.
 2. An electrical generator as defined in claim 1 including a plurality of axially extending elongated ribs between and interconnecting the two casing walls.
 3. An electrical generator as defined in claim 2 wherein the ribs are circumferentially spaced apart, a magnetic core being located between each two successive ribs.
 4. An electrical generator as defined in claim 1 wherein the casing walls define between them an annular conduit, and means for passing a cooling fluid through the conduit to cool the stator.
 5. An electrical generator as defined in claim 4 including a plurality of axially extending elongated ribs between and interconnecting the two casings, each rib extending radially across the conduit, and the ribs having holes in them to permit circulation of the cooling fluid through them to the cores and windings of the stator.
 6. An electrical generator as defined in claim 1 wherein the rotor comprises a magnet having two axially spaced apart poles, a plurality of pole pieces projecting radially from a first of the poles, the first pole pieces being circumferentially spaced apart, a plurality of fingers extending from the second pole toward the first pole, a plurality of second pole pieces projecting radially from the fingers, the second pole pieces being in the spaces between the first pole pieces.
 7. An electrical generator as defined in claim 6 wherein the fingers extend in an axial direction, each finger having a radially outward 90° bend near its free end, the second pole pieces being defined by the radially outward portions of the fingers beyond the 90° bends.
 8. An electrical generator as defined in claim 6 wherein at one end of the stator all the core ends lie in a single plane perpendicular to the casing axis, and all the pole pieces lie in a single plane parallel to, and axially spaced from, the plane containing the core ends.
 9. An electrical generator as defined in claim 6 wherein the rotor includes a core carrying an electric coil and a disk at each end of the core, the first pole pieces being formed in the edge of one disk, and the fingers and second pole pieces extending from the other of the disks.
 10. An electrical generator as defined in claim 1 wherein each magnetic core is a stack of magnetic laminates.
 11. An electrical generator as defined in claim 10 wherein each magnetic core has a rectangular cross-sectional shape.
 12. An electrical generator as defined in claim 10 wherein each magnetic core has a radially inward 90° bend at one end to give the core an L-shaped configuration having a long leg and a short leg, the long legs of the cores extending axially between the casing walls and the short legs extending radially inwardly, and a laminated ring surrounding the casing axis and fixed to each of the short legs.
 13. An electrical generator as defined in claim 1 wherein each magnetic core is a molding of iron powder and a polymer.
 14. An electrical generator as defined in claim 1 wherein each magnetic core is a sintered article of iron powder, non-magnetic metal powder, and a ceramic oxide. 